ACTG 359: The purpose of this study is to determine whether treatment with the soft gelatin capsule of saquinavir (SQV) in combination with ritonavir or nelfinavir and other drugs that fight HIV (delavirdine and adefovir dipivoxil) will decrease the amount of HIV virus in your blood or have an effect on the number of immune system cells (cells that fight infection). A second purpose of the study is to find out if the study drug combinations are safe and how well they are tolerated. Information about the safety and tolerance of the drug combinations to be used in this study is not available.